"Valleri" b/w "Tapioca Tundra"

According to Andrew Sandoval's The Monkees: The Day-by-Day Story of the 60s TV Pop Sensation, "Valleri" b/w "Tapioca Tundra" - the Monkees' sixth single (Colgems 1019) - was released in the U.S. fifty years ago this month (February 1968).  Sandoval lists two different dates for the U.K. release.  In the same box that details the U.S. release, he notes that the U.K. single (RCA 1673) was released in April, but later in the chronology, he says it was released on 22 March.